While placebo effects are well recognized within clinical medicine, “nocebo effects” have received much less attention. Nocebo effects are problems caused by negative expectations derived from information or treatment provided during a clinical interaction. In this review, we examine how nocebo effects may arise following pediatric concussion and how they may worsen symptoms or prolong recovery. We offer several suggestions to prevent, lessen, or eliminate such effects. We provide recommendations for clinicians in the following areas: terminology selection, explicit and implicit messaging to patients, evidence-based recommendations, and awareness of potential biases during clinical interactions. Clinicians should consider the empirically grounded suggestions when approaching the care of pediatric patients with concussion.
Michael W. Kirkwood, David R. Howell, Brian L. Brooks, Julie C. Wilson, and William P. Meehan III
Lauren A. Brown, Eric E. Hall, Caroline J. Ketcham, Kirtida Patel, Thomas A. Buckley, David R. Howell, and Srikant Vallabhajosula
Context: Sports often involve complex movement patterns, such as turning. Although cognitive load effects on gait patterns are well known, little is known on how it affects biomechanics of turning gait among athletes. Such information could help evaluate how concussion affects turning gait required for daily living and sports. Objective: To determine the effect of a dual task on biomechanics of turning while walking among college athletes. Design: Cross-sectional study. Setting: University laboratory. Participants: Fifty-three participants performed 5 trials of a 20-m walk under single- and dual-task conditions at self-selected speed with a 180° turn at 10-m mark. The cognitive load included subtraction, spelling words backward, or reciting the months backward. Interventions: Not applicable. Main Outcome Measures: Turn duration, turning velocity, number of steps, SD of turn duration and velocity, and coefficient of variation of turn duration and velocity. Results: Participants turned significantly slower (155.99 [3.71] cm/s vs 183.52 [4.17] cm/s; P < .001) and took longer time to complete the turn (2.63 [0.05] s vs 2.33 [0.04] s; P < .001) while dual tasking, albeit taking similar number of steps to complete the turn. Participants also showed more variability in turning time under the dual-task condition (SD of turn duration = 0.39 vs 0.31 s; P = .004). Conclusions: Overall, college athletes turned slower and showed more variability during turning gait while performing a concurrent cognitive dual-task turning compared with single-task turning. The slower velocity increased variability may be representative of specific strategy of turning gait while dual tasking, which may be a result of the split attention to perform the cognitive task. The current study provides descriptive values of absolute and variability turning gait parameters for sports medicine personnel to use while they perform their concussion assessments on their college athletes.